If your workflow absolutely requires an old version of Waterfox, implement these safety measures:

If you accidentally updated to a newer Classic version and want to go back:

Web browsers are a primary target for hackers. Newer versions include critical security patches that protect you from malware, data theft, and phishing. Running an old version leaves your system exposed to known exploits.

: Over time, websites update their code. Older engines will experience broken layouts, non-functional scripts, and frequent script errors on modern sites like YouTube, banking portals, or Google Workspace. How to Mitigate Risks on Older Versions

On Windows, press Win + R , type waterfox.exe -P , and press Enter. Create a new profile specifically for this older version. Crucial Post-Installation Steps